Inland Dunes Research Articles

Die epigäische Spinnenfauna (Arachnida, Araneae) in Sandrasen, Borstgrasrasen und Ruderalfluren im Naturschutzgebiet „Alter Flugplatz Karlsruhe“

The epigeic spider assemblages (Arachnida, Araneae) of dry acid grassland, mat-grass and ruderal vegetation in a nature protection area in the upper Rhine valley. epigeic spiders were sampled using pitfall traps during one year in an anthropogenic open site within the city of karlsruhe (Alter Flugplatz karlsruhe). The area, historically used as a military parade ground and airport, is protected as a Special Area of conservation (SAc) within the Natura 2000 network of the eU and since 2010 as a German nature reserve. We were interested in the diversity, assemblage structure and distribution of spider species within the area and investigated three different plant formations: sparse grass-dominated vegetation with frequent open sand patches (sandy turf ), closed grassland dominated by the mat-grass (Nardus stricta) and ruderal vegetation with blackberry bushes. 123 species were identified from these captures, including many specialists of xerothermic habitats and rare and endangered species like Alopecosa striatipes, Agroeca lusatica, Haplodrassus dalmatensis, Styloctetor romanus, Typhochrestus simoni and Xysticus striatipes as well as extremely rare species of unclassified red list status like Mysmenella jobi, Theonoe minutissima and Zora parallela. The three investigated habitat types were quite similar concerning α-diversity, while measures of β-diversity indicated a strong species turnover. By performing an ecological habitat analysis (using autecological data on spiders) essential differences between the three habitat types could not be discovered, especially not between mat-grass and sandy turf. However, analysing the guild structures showed that different ways of using habitat resources dominated in the different habitat types. For Nardus-grassland several species could be identified as indicator species. While many xeroand photophiles live in the open grassland, the stenotopic psammophiles of inland dunes in the region were not found. The ruderal area houses a mix of grasslandand forest species.

Effect of geomorphology and nitrogen deposition on rate of vegetation succession in inland drift sands

AbstractQuestions(1) At what rate does succession take place in active and more stabilized drift sands in regions with low and high N deposition in the Netherlands? (2) What is the present composition of pioneer vegetation in active and more stabilized drift sands in regions with low and high N deposition? (3) What efforts are necessary to conserve bare sand in drift sands?LocationEight inland dunes in the Netherlands, which represent four active and four more stabilized drift sands in regions with low and high N deposition.MethodsAerial photographs from 1950, 1981, 1995 and 2007 were used to compare rates of succession from bare sand towards forest. For each site, a detailed vegetation map was made in 2007.ResultsIn all studied sites, bare sand decreased, especially in regions with high N deposition. This decline was significantly higher between 1981 and 2007 than between 1950 and 1981. The loss of bare sand did not lead to an increase of pioneer vegetation, which remained more or less stable; it led, however, to an increase of heath and forest. In active drift sands, pioneer vegetation was characterized by Corynephorus canescens and Polytrichum piliferum, while lichens, lichen‐rich grassland and Campylopus introflexus were more common in stabilized drift sands. In regions with high N deposition, the proportion of Campylopus introflexus to older pioneer stages was significantly higher, and the contribution of forest to the ‘heath/forest’ vegetation class was also higher. The calculated life span of bare sand decreased in all sites. Extrapolation of the results suggests that in the absence of restoration measures, bare sand will vanish by 2035.ConclusionsIn both active and more stabilized drift sands, a generic loss of bare sand and an increase in forest area was found. The increase was higher in regions with high N deposition. Conservation management should include the annual transformation of 43 ha of forest into bare sand in order to stop the loss of bare sand.

Chronic wind and plant communities in dunes: Total biomass, inter-specific competition, and species abundance

Chronic wind is an important ecological factor, but its direct roles in shaping plant communities remain poorly understood. We hypothesized that chronic wind can modulate community productivity, inter-specific competition, and species abundance in inland dunes. We conducted an experiment with three shrubs (Artemisia ordosica, Caragana intermedia, and Hedysarum laeve) common to semi-arid sandlands, set up seven kinds of plant communities (i.e. Artemisia monoculture, Caragana monoculture, Hedysarum monoculture, Artemisia–Caragana mixture, Artemisia–Hedysarum mixture, Caragana–Hedysarum mixture, and Artemisia–Caragana–Hedysarum mixture), and communities subjected to two levels of wind exposure: shielded (by means of fencing) or exposed (no fencing). We measured total biomass per plot, competitive effects, and relative species abundance. Wind exposure did not significantly affect the total biomass of monocultures but increased their root weight ratio. However, wind exposure enhanced the total biomass of three-species mixtures but not two-species mixtures, and had no effects on root weight ratio of all mixtures. Wind exposed condition increased the competitive ability and relative abundance of Artemisia, decreased the competitive ability of Hedysarum but had no effects on its abundance, and did not affect the competitive ability of Caragana but decreased its abundance. These results suggest that chronic wind, as an environmental filter, can directly modulate plant communities through altering competitive outcomes and thus affect community functioning.

Dew formation on the surface of biological soil crusts in central European sand ecosystems

Abstract. Dew formation was investigated in three developmental stages of biological soil crusts (BSC), which were collected along a catena of an inland dune and in the initial substrate. The Penman equation, which was developed for saturated surfaces, was modified for unsaturated surfaces and used for prediction of dewfall rates. The levels of surface saturation required for this approach were predicted using the water retention functions and the thicknesses of the BSCs. During a first field campaign (2–3 August 2011), dewfall increased from 0.042 kg m−2 for the initial sandy substrate to 0.058, 0.143 and 0.178 kg m−2 for crusts 1 to 3, respectively. During a second field campaign (17–18 August 2011), where dew formation was recorded in 1.5 to 2.75-h intervals after installation at 21:30 CEST, dewfall increased from 0.011 kg m−2 for the initial sandy substrate to 0.013, 0.028 and 0.055 kg m−2 for crusts 1 to 3, respectively. Dewfall rates remained on low levels for the substrate and for crust 1, and decreased overnight for crusts 2 and 3 (with crust 3 > crust 2 > crust 1 throughout the campaign). Dew formation was well reflected by the model response. The suggested mechanism of dew formation involves a delay in water saturation in near-surface soil pores and extracellular polymeric substances (EPS) where the crusts were thicker and where the water capacity was high, resulting in elevated vapor flux towards the surface. The results also indicate that the amount of dewfall was too low to saturate the BSCs and to observe water flow into deeper soil. Analysis of the soil water retention curves revealed that, despite the sandy mineral matrix, moist crusts clogged by swollen EPS pores exhibited a clay-like behavior. It is hypothesized that BSCs gain double benefit from suppressing their competitors by runoff generation and from improving their water supply by dew collection. Despite higher amounts of dew, the water availability to the crust community decreases with crust development, which may be compensated by ecophysiological adaptation of crust organisms, and which may further suppress higher vegetation or mosses.

Succession of N cycling processes in biological soil crusts on a Central European inland dune

Biological soil crusts (BSCs) are microbial assemblages that occur worldwide and facilitate ecosystem development by nitrogen (N) and carbon accumulation. N turnover within BSC ecosystems has been intensively studied in the past; however, shifts in the N cycle during BSC development have not been previously investigated. Our aim was to characterise N cycle development first by the abundance of the corresponding functional genes (in brackets) and second by potential enzyme activities; we focussed on the four processes: N fixation (nifH), mineralisation as proteolysis and chitinolysis (chiA), nitrification (amoA) and denitrification (nosZ). We sampled from four phases of BSC development and from a reference located in the rooting zone of Corynephorus canescens, on an inland dune in Germany. BSC development was associated with increasing amounts of chlorophyll, organic carbon and N. Potential activities increased and were highest in developed BSCs. Similarly, the abundance of functional genes increased. We propose and discuss three stages of N process succession. First, the heterotrophic stage (mobile sand without BSCs) is dominated by mineralisation activity. Second, during the transition stage (initial BSCs), N accumulates, and potential nitrification and denitrification activity increases. Third, the developed stage (established BSCs and reference) is characterised by the dominance of nitrification.

Nitrogen deposition and soil carbon content affect nitrogen mineralization during primary succession in acid inland drift sand vegetation

Two inland dunes in the Netherlands receiving low (24) and high (41 kg N ha−1 yr−1) nitrogen (N) deposition were compared for N dynamics and microbial activity to investigate the potential effect of N on succession rate of the vegetation and loss of pioneer habitats. Primary succession stages were sampled, including bare sand, and vegetation dominated by Polytrichum piliferum, Campylopus introflexus, lichens and grasses respectively, representing a series of vegetation types in undisturbed drift sand sites with succession starting on bare sand containing virtually no organic matter. Microbial characteristics and potential N mineralization were analysed in a laboratory experiment. Organic matter accumulated during succession, resulting in a lower pH and in higher microbial biomass (bacteria and fungi), respiration and net N mineralization. The increase in respiration and N mineralization was largely due to the development of an ectorganic layer in the middle stages of succession. The observed effects of N deposition were (1) decrease of microbial biomass, (2) higher net N mineralization per m2, (3) higher levels of free nitrogen in the soil, and (4) a higher microbial N:P ratio. Elevated N deposition leads to higher N availability which may cause accelerated succession.

Response of inland dune vegetation to increased nitrogen and phosphorus levels

AbstractQuestionHow does pioneer vegetation of acid inland dunes respond to addition of nitrogen (N) and phosphorus (P)?LocationTwo inland dune reserves in The Netherlands with low and high N deposition.MethodsDuring 2.5 yr, N and P addition (control, N, P, NP) took place in three different vegetation types of inland dunes (Polytrichum piliferum mats, Campylopus introflexus mats and lichen‐dominated vegetation). In each site, changes in the vegetation were recorded in three replicate quadrats of 1 m × 1 m per treatment. Differences in element content of grasses and lichens were recorded, together with vegetation parameters, including cover and height of grasses, bryophytes and lichens.ResultsIn the site with high N deposition, grasses were taller, had higher N:P ratios and a generally lower lichen cover than in the low‐deposition area. Experimental N application resulted in higher N and lower base metal concentrations in grasses and an increase in grass cover and size. In contrast, lichens showed a general decline in the N treatment and the lichen:grass ratio decreased. The effect of N addition was larger in the low‐deposition area. The P treatment had an opposite effect: lichens increased in size and cover and overgrew grasses, especially when reindeer lichens were present. This suggests that the cryptogam layer was P‐limited even in the low N deposition site.ConclusionsPioneer vegetation in inland dunes is susceptible to N and P addition. The results provide evidence for a decrease in lichen cover due to increased N deposition.

Wood charcoal from an inland dune complex at Joldelund (Northern Germany). Information on Holocene vegetation and landscape changes

The charcoal content of an inland dune complex close to Joldelund in Northern Germany was analysed as part of a project which aims to reconstruct Holocene aeolian activity in high spatial and temporal resolution. The eleven investigated profiles contained numerous charcoal-enriched layers, providing evidence for the potential of inland dunes as palaeoarchives for anthracology. Earlier studies have found Late Roman Iron Age settlement activity and iron ore productions in the research area and in its vicinity. Charcoal assemblages date to Roman Iron Age as well as Early, High and Late Medieval Times, according to radiocarbon dating of single, species-identified charcoal fragments and the stratigraphic correlation of sedimentary units. The dominance of Quercus (oak) and significant proportions of Ericaceae-charcoal (probably Calluna vulgaris, heather) especially in the Early and High Medieval samples indicate the presence of a heathland with Quercus trees, which was managed by fire. In the younger layers of sand, a greater diversity of taxa were found, including the dominant Quercus, Fagus (beech), Alnus (alder), Betula (birch), Corylus (hazel), Fraxinus (ash), Salix (willow), Populus-Salix (poplar-willow-type), Acer (maple), Pinus (pine), Maloideae (apple subfamily), Tilia (lime), as well as some Ericaceae. The diversity of species indicates that some charcoals were transported by wind together with the sand from the surrounding areas, and do not represent the local vegetation on the dunes, but rather a nonspecific regional input. The differences in the charcoal assemblages and thus the possible correlation of aeolian units support the stratigraphic correlation of the sedimentary aeolian units. The comparison with the available pollen data from nearby mires showed a good agreement of the proportions of woody taxa, with only few exceptions.

Reply to the comment on “Shoreface sand supply and mid- to late Holocene aeolian dune formation on the storm dominated macrotidal coast of the southern North Sea” by E.J. Anthony, M. Mrani-Alaoui and A. Héquette [Marine Geology 276 (2010) 100–104

Baeteman and Mauz (2012) raise three main points of disagreement with Anthony et al. (2010) regarding the probable age and mode of formation of an inland dune on the North Sea coastal plain of France: (1) the proposed chronology of dune formation, (2) the interpretation of the stratigraphic data from the dune, and (3) the proposed model of dune formation. The chronology proposed as an alternative by Baeteman and Mauz (2012) is not based on radiometric ages directly derived from this inland dune. Baeteman and Mauz (2012) propose a sea-level-driven mechanism of coastal evolution that fails to demonstrate how this dune was formed, and they do not provide any evidence in support of what they refer to as a ‘surge drift line’ involved in the formation of this dune, nor of the mechanisms of dune formation. We highlight numerous flaws in the comments and interpretations of Baeteman and Mauz (2012) that demonstrate failure to take into account recent findings on the main sediment-transport mechanisms and morpho-sedimentary outcomes characterising the shallow, sediment-rich, mixed storm- and tide-dominated macrotidal shoreface of the southern North Sea, compounded by an inadequate understanding of morphodynamic processes and sediment-supply conditions involved in coastal progradation.

Arthropod assemblages of the Quebrada del Morel private protected area (Atacama Region, Chile)

The objective of this baseline study was to use pitfall traps to examine the taxonomic composition and abundance of arthropods in the Quebrada del Morel private protected area located in the Atacama Region (Chile). The study area was divided into 10 vegetationally and pedologically contrasting sites: coastal steppe (CS), ravine bottom (RB), dunes with Prosopis flexuosa (PF), sandy-bottomed ravine (SBR), dunes with Skytanthus acutus (SA), coastal range (CR), piedmont with Nolana sp. (PN), inland dunes (ID), steppe with Nolana sp. (EN), and steppe with Atriplex sp. (EA). A total of 2187 specimens were captured, belonging to 73 species in 31 families. Of these 73 species, 26 belonged to Arachnida, and 47 to Insecta. The two dominant orders of the Arachnida assemblage were Solifugae (22.8% of total capture) and Araneae (5.7%). Insecta accounted for 69.1% of the total capture and was dominated by two orders: Coleoptera (33.8%) and Orthoptera (21.9%). The most abundant arthropod families were the solifuge Mummucidae (22.5%), the coleopteran Tenebrionidae (19.4%), and the orthopteran Gryllidae (18.8%). Particularly important among these families was Tenebrionidae which was represented by 18 species and 11 genera. The sites with the highest abundance of tenebrionids were PF (61.9%) and SBR (11.8%). The highest species diversity was observed in SBR (13) and PF (11). The differences in vegetation between the sites were clearly reflected in the numerical contribution of most taxa. This information will help implement compensation actions, develop a reclamation plan, and consolidate a conservation management plan for the Quebrada del Morel private protected area.

OSL dating of an inland dune along the lower River Scheldt near Aard (East Flanders, Belgium)

AbstractThe chronostratigraphic position of aeolian dunes in East Flanders (Belgium) has been under debate for decades. Until now, the only available age information consisted of a limited number of radiocarbon dates, which provided indirect sediment deposition chronologies. This paper reports on the first direct determination, by quartz-based single-aliquot optically stimulated luminescence dating, of the time that dune sands were deposited along the Lower River Scheldt in Belgium. The sediments are dated at 12.0±0.9 ka (n = 5), which confirms that the time of inland dune formation in East Flanders dates from the Younger Dryas period and should not be constrained to the Holocene.

Comments on “Shoreface sand supply and mid- to late Holocene aeolian dune formation on the storm-dominated macrotidal coast of the southern North Sea” by E.J. Anthony, M. Mrani-Alaoui and A. Héquette [Marine Geology 276 (2010) 100-104

Anthony et al. (2010) published a recent paper in Marine Geology on the origin and chronology of an inland dune for which they presented an explanation for the regional pattern of mid- to late Holocene coastal development. This explanation contradicts other data collected from this coastal area. It is moreover in contrast to our current understanding of Holocene coastal evolution of the Southern North Sea. The data used by Anthony et al. (2010) includes a number of inconsistencies that led the authors to incorrect conclusions. This discussion reports on our critical evaluation of data and reasoning in Antony et al. (2010). We propose an alternative model of coastal evolution which is in line with the current knowledge about mid- to late Holocene coastal evolution.

Evolution of late Holocene coastal dunes in the Cauvery delta region of Tamil Nadu, India

Widespread occurrences of coastal dunes are observed in the Cauvery delta region of Tamil Nadu in Vedaranniyam in the south east coast of India. These dunes were studied to establish the chronology of their formation and to understand their evolution using optically stimulated luminescence (OSL) dating in combination with sedimentological studies (quartz grain surface morphology using scanning electron microscope, grain size and heavy mineral analysis). The study shows that on the south-east coast of India widespread periodic dune formation/reactivation has taken place during the late Holocene to very recent times due to a variety of reasons such as climatic variation and land use changes. The sand mobility index shows that the dunes in the area have been largely active during the past century in the southern part in Nagapattinam region and many of the crests were active in the northern Cauvery delta in Cuddalore region. The angularity and fresh appearance of sand in the inland dunes suggest a short distance of sand transport and a source proximal sand deposition was proposed for the dune formation. The study demonstrates the sensitivity of sand dunes on the south east coast of India to varying climatic conditions and changes in regional land use.

Building of shore-oblique transverse dune ridges revealed by ground-penetrating radar and optical dating over the last 500 years on Tottori coast, Japan Sea

Coastal dunes provide valuable information on the past aeolian activity. Better characterization of internal dune structures and their chronology potentially can greatly improve the interpretation of past environmental changes. Ground-penetrating radar (GPR) and optically-stimulated luminescence (OSL) dating was applied to two transverse dune ridges which are arranged obliquely to the shoreline on the Tottori coast, Japan Sea. Data shows that the inner ridge has a core of Pleistocene dune draped with Holocene sand, while the outer ridge consists only of Holocene sand. The Holocene dune is generally dominated by landward migration, but the outer ridge shows a clear seaward accretion during the 18th century AD. OSL dating showed concordant results with radar stratigraphy and topographic changes since AD 1932 revealed by maps. From this we were able to present the first detailed report of the multi-decadal- to centennial-scale dune formation for the last 500 years in East Asia, contemporaneous with the Little Ice Age, during which many European coastal and inland dunes were activated. In East Asia, it is thought that the winter monsoon plays an important role for aeolian processes. The seaward migration during the 18th century reflects a decrease in wind capacity, which restricted sand transport nearshore, being related to decline in winter monsoon revealed by Chinese historical documents. In contrast, two remarkable events of landward accretion occurred in AD 1580–1640 and around AD 1840, respectively, corresponding to periods of increased dust fall in China, which suggest enhanced winter monsoon. The zone of maximum sedimentation shifted through time from the inner to outer ridges, and also towards the seaward end of the shore-oblique dune ridge, reflecting an expansion of the dune field caused by shoreline progradation. These suggest that the effective combination of GPR and OSL dating was critical in detailed characterization of the complicated depositional pattern of the transverse dune ridge, and thus in reconstruction of the past aeolian activity.

Eolian dynamics and sediment mixing in the Gran Desierto, Mexico, determined from thermal infrared spectroscopy and remote-sensing data

The Gran Desierto dune field is only partially composed of quartz-rich sands from the ancestral Colorado River. Local sources have been previously underestimated as a major source of sand because previous remote-sensing studies were limited in their capability to detect silicate minerals. Compositions of sands were evaluated in this study using a combination of laboratory thermal emission spectroscopy and thermal remote-sensing data acquired from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument. The spatial interpolation of sample compositions allowed visualization of the sand transport pathways from feldspar-rich local sources by revealing gradients of composition between the dune field and surrounding local sources. The laboratory data were comparable to the remote-sensing retrievals of quartz and feldspar abundance. The mineralogical maturity of the Desierto dunes could be determined by the quartz/feldspar ratio, therefore providing a context for understanding the provenance of the Gran Desierto in relation to other Mojave and Sonoran dune fields. The composition of a previously undescribed group of dunes east of the Pinacate, the Sonoyta dunes, was measured as higher in potassium feldspar relative to the rest of the dune field. The composition of Sonoyta dunes is characteristic of other Mojave dune fields, which are more isolated near local feldspar-rich sources. South of the Pinacate, quartz-rich sand from the west admixes with feldspar-rich sand from the Sonoyta dunes to the east. The northern margin of the Gran Desierto is similarly enriched in feldspar from alluvial fans, and the coastal sand is influenced by carbonate sand that does not appear to survive transport to the inland dunes.

Invasiveness of Campylopus introflexus in drift sands depends on nitrogen deposition and soil organic matter

Question: Does the neophyte moss Campylopus introflexus invade more often in drift sand pioneer vegetations under high nitrogen (N) deposition? Location: Fourteen inland dune reserves in The Netherlands over a gradient of atmospheric N deposition. Methods: A transect study, dispersal experiment and culture experiment were carried out. In the transect study, the establishment of C. introflexus and lichens was measured in pure mats of Polytrichum piliferum, an early succession stage. The overall presence of C. introflexus in the area was also estimated. In the dispersal experiment, fragments of C. introflexus and lichen species were sown in P. piliferum mats at two sites with high and low N deposition. In the culture experiment C. introflexus fragments were grown on soil with different carbon (C) content and N dose. Results: The Campylopus:lichen ratio was positively correlated (r2=0.61) with the atmospheric ammonia concentration. Campylopus began to dominate at an ammonia air concentration of 7 μg m−3, correlated with the overall presence of the species in the sites investigated. Survival of sown Campylopus fragments was significantly higher and the endangered lichen Cladonia strepsilis significantly lower in the site with a high ammonia concentration. Survival of Cladonia coccifera and Cladonia portentosa was high at both sites. Experimental growing of C. introflexus showed significant responses to both C content and N, although C content showed the strongest effect. Conclusions: Growth of C. introflexus is affected by soil C content and N deposition. Inland dune reserves under high N deposition risk loss of lichen-dominated vegetations because of moss encroachment.

Shoreface sand supply and mid- to late Holocene aeolian dune formation on the storm-dominated macrotidal coast of the southern North Sea

Although pulses of coastal dune development in the course of the Holocene have been attributed to variations in the availability of sand, to modulation of sand supply by sea level change, and to changes in wind conditions, identifying the processes driving such pulses has been rather elusive. The shore deposits bordering the tide- and storm wave-dominated southern North Sea evince complex mid- to late Holocene stratigraphy and sediment heterogeneity. These deposits include a unique 7 km-long, 0.3–0.6 km-wide, and up to 7 m-high aeolian sand unit, the Ghyvelde dune, occurring astride the French–Belgian border in an apparently ‘anomalous’ inland location. The dune overlies, and is surrounded by, tidal sandy and muddy deposits incorporating freshwater peat. Data from four mechanical cores and eight auger holes, and three radiocarbon ages and one OSL age suggest that this inland dune was part of an ancestral North Sea sand flat and mudflat environment. Confronting the dune stratigraphy with the prevailing tide- and storm-controlled dynamics of shoreline progradation in this area indicates that dune formation occurred under a pulse of abundant sand supply resulting from the attachment, to a mid-Holocene North Sea tidal-flat shore, of a shoreface tidal bank under repeated storms. This mode of onshore sand supply generates extremely rapid progradation (up to 1 km over a century) of the sand flat shore, the surface of which serves as a large aeolian fetch zone for active backshore dune accumulation, while parts of this surface trap, locally, significant amounts of mud that are subsequently fossilised by aeolian sand. The potential influence of sea level and storminess in modulating the timing of shoreface sand supply and late Holocene coastal dune development in the southern North Sea, reported in studies from other areas, remains to be established.

Variability of the structure and directions in the development of heaths and psammophilous grasslands within the artillery range near the city of Toruń

Phytosociological analysis of non-forest communities was carried out on one of the oldest and the biggest military training grounds in Europe, located near the city of Toruń, in central Poland. Heaths and psammophilous grasslands developed here as a result of deforestation of inland dunes in the valley of the Vistula River, as well as a result of destruction of soils and vegetation brought on by manoeuvres and artillery firings. They form a landscape mosaic with young self-seeding pines, mature pine forests and birch forests. Using the Braun-Blanquet method, 84 relevés were made in the areas dominated by dwarf shrubs and 32 relevés within psammophilous grasslands. Applying the classic phytosociological method, the following plant associations were distinguished in the first set of relevés: Pohlio-Callunetum and Arctostaphylo-Callunetum, as well as the community with Cytisus scoparius. Within the psammophilous grasslands, two associations were distinguished: Spergulo vernalis-Corynephoretum and Calamagrostietum epigeji. In this paper, the heterogeneity within associations and communities was presented together with descriptions of individual syntaxa, as well as dynamic and developmental relationships between the aforementioned were identified.

Variability of the structure and directions in the development of heaths and psammophilous grasslands within the artillery range near the city of Toruń

Phytosociological analysis of non-forest communities was carried out on one of the oldest and the biggest military training grounds in Europe, located near the city of Toruń, in central Poland. Heaths and psammophilous grasslands developed here as a result of deforestation of inland dunes in the valley of the Vistula River, as well as a result of destruction of soils and vegetation brought on by manoeuvres and artillery firings. They form a landscape mosaic with young self-seeding pines, mature pine forests and birch forests. Using the Braun-Blanquet method, 84 relevés were made in the areas dominated by dwarf shrubs and 32 relevés within psammophilous grasslands. Applying the classic phytosociological method, the following plant associations were distinguished in the first set of relevés: Pohlio-Callunetum and Arctostaphylo-Callunetum, as well as the community with Cytisus scoparius. Within the psammophilous grasslands, two associations were distinguished: Spergulo vernalis-Corynephoretum and Calamagrostietum epigeji. In this paper, the heterogeneity within associations and communities was presented together with descriptions of individual syntaxa, as well as dynamic and developmental relationships between the aforementioned were identified.

Fine-scale patterns in the distribution of semi-arid tree species at Wyperfeld National Park, southeastern Australia – The potential roles of resource gradients vs disturbance

Relatively little is known of the environmental determinants of fine-scale patterns of tree distribution and regeneration on inland dune systems in semi-arid regions. Trees in semi-arid regions can experience extremes of temperature, and resource availability can vary both temporally and spatially. Climate change may disrupt these fine-scale patterns and alter patterns at the landscape level. Here we investigate potential influences of environmental factors and disturbance on fine-scale distribution patterns in four tree species across a predicted aridity gradient along four inland dunes in semi-arid southeastern Australia. The tree species were restricted to narrow topographic ranges, occurring sequentially up dune slopes. Relatively little variation was detected in conditions experienced by each species, except for the contrasting soils of the alluvial flat at the base of the dunes. Fine-scale gradients in resource availability and microclimate, together with variation in site-specific fire and flood history on these dunes, appear to be determining tree distribution patterns. Landscape-level species coexistence and diversity may decline if fine-scale topographic differences and disturbance regimes are disrupted by climate change.